Cuffed tracheostomy (trach) tubes are often used to ventilate hospitalized patients for longer periods of time; endotracheal (ET) tubes being used for periods less than a week to 10 days. Trach tubes are inserted through the throat, into the trachea and the proximal end then typically connected to a mechanically supplied source of breathing air, i.e., from a ventilator or respirator. The cuffs or “balloons” are located on the distal end of the trach tube and block the patient's trachea so that inhalation and exhalation are performed only through the tube. The balloon also functions to block liquid secretions from passing downwardly into the lungs and potentially causing ventilator acquired pneumonia (VAP). Secretions are held above the balloon and may be periodically removed to help ensure they do not enter the lungs.
Cuffs for use on ET and trach tubes were, for many years, high-pressure, low-volume balloons. These balloons also had relatively thick walls made from polyolefins and polyvinyl chlorides. Wall thicknesses could be of the order of from 60 to 150 microns or more, making for a relatively cumbersome balloon but one that was unmistakably strong. These “HPLV” balloons were found to be the cause of substantial trauma to the tracheal tissue since they forcefully compressed the tracheal walls. Adverse patient outcomes and lengthened recovery times prompted medical professionals and researchers to search for a less traumatic device with which to obdurate the trachea for assisted mechanical ventilation.
In the last few decades balloons have been developed that are much lower in pressure and higher in volume. These HVLP balloons present a greater surface area of contact with the tracheal wall and so are able to lay against the wall using much less pressure per square centimeter. These balloons, however, remained relatively thick; still on the order of 60 to 150 microns. Trauma was positively impacted by these newer balloons though room for improvement remained.
A more recent development in has been thinner walled HVLP balloons like those disclosed in U.S. Pat. No. 6,526,977 to Gobel. Gobel teaches oversized balloons with a wall thickness so low that they form folds against the tracheal wall that are so small that secretions cannot pass through. Likewise, U.S. Pat. No. 6,612,305 teaches a recently developed balloon that provides better control over the location of the balloon but that appears to seal the tracheal stoma, thus limiting access to that region.
A balloon and a method of making a balloon that is more stable in the trachea than current balloons, and that is thin and compliant would therefore be desirable.